The present invention is mainly directed to a knowledge support and flexible dialogue control system.
Automatic telephone conversation systems, which are activated in response to a user's request through speech for providing information and service, are well known in the IT industry. An automatic telephone conversation system may contain the components such as a speech recognition engine, a text to speech engine, a natural language understanding engine, a dialogue control engine and some business servers. The dialogue control system may further include a dialogue grammar engine for modeling dialogue structures and for guiding the procedure of satisfying user needs.
Several known telephone conversation systems include a dialogue control and dialogue grammar system. The dialogue control system could consist of user intention determination based on dialogue act sequencing. A controller, which is connected to one or a combination of these dialogue grammar models, controls the system dialogue moves in accordance with the user intention decided at a point of the dialogue. In response to the understood user intention, one or more deployment aspects of the telephone conversation system, such as a database server, may be accessed. A conversation system with flexible aspects of dialogue moves control is commonly referred to as a “mixed-initiative” dialogue system.
Dialogue grammar and dialogue control engines are key components of mixed-initiative telephone conversation systems. There are several types such systems but many of them suffer from serious shortcomings. A system that relies on a generative dialogue act grammar may hardly capture the full flexibility of the conversation flow, for instance. A system that retains the interactive information between the user and the system in the local grammar tree recently generated suffers from the inflexibility of knowledge representation as well as limitation of the locality of the temporal scope. A system that relies solely on the grammar structure to capture the user's knowledge, intention or indication cannot account for other aspects of the knowledge structure, such as the ontological structure, for instance.